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Bauer MR, McVey MM, Boehm SL. Drinking history dependent functionality of the dorsolateral striatum on gating alcohol and quinine-adulterated alcohol front-loading and binge drinking. Alcohol 2022; 105:43-51. [PMID: 36240946 PMCID: PMC9835618 DOI: 10.1016/j.alcohol.2022.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 09/13/2022] [Accepted: 09/29/2022] [Indexed: 01/26/2023]
Abstract
After an extended alcohol-drinking history, alcohol use can transition from controlled to compulsive, causing deleterious consequences. Alcohol use can be segregated into two distinct behaviors, alcohol seeking and alcohol taking. Expression of habitual and compulsive alcohol seeking depends on the dorsolateral striatum (DLS), a brain region thought to engage after extended alcohol access. However, it is unknown whether the DLS is also involved in compulsive-like alcohol taking. The purpose of this experiment was to identify whether the DLS gates compulsive-like binge alcohol drinking. To ask this question, we gave adult male and female C57BL/6J mice a binge-like alcohol-drinking history, which we have previously demonstrated to produce compulsive-like alcohol drinking (Bauer, McVey, & Boehm, 2021), or a water-drinking history. We then tested the involvement of the DLS on gating binge-like alcohol drinking and compulsive-like quinine-adulterated alcohol drinking via intra-DLS AMPA receptor antagonism. We hypothesized that pharmacological lesioning of the DLS would reduce compulsive-like quinine-adulterated alcohol (QuA) drinking, but not non-adulterated alcohol drinking, in male and female C57BL/6J mice. Three important findings were made. First, compulsive-like alcohol drinking is significantly blunted in cannulated mice. Because of this, we conclude that we were not able to adequately assess the effect of intra-DLS lesioning on compulsive-like alcohol drinking. Second, we found that the DLS gates binge-like alcohol drinking initially, which replicates findings in our previous work (Bauer, McVey, Germano, Zhang, & Boehm, 2022). However, following an extended alcohol history, the DLS no longer drives this behavior. Finally, alcohol and QuA front-loading is DLS-dependent in alcohol-history mice. Intra-DLS NBQX altered these drinking behaviors without altering ambulatory locomotor activity. These data demonstrate the necessity of the DLS in binge-like alcohol drinking before, but not following, an extended binge-like alcohol-drinking history and in alcohol front-loading in alcohol-history mice.
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Affiliation(s)
- Meredith R Bauer
- Indiana Alcohol Research Center and Department of Psychology, Indiana University - Purdue University Indianapolis, Indianapolis, IN 46202, United States
| | - Megan M McVey
- Indiana Alcohol Research Center and Department of Psychology, Indiana University - Purdue University Indianapolis, Indianapolis, IN 46202, United States
| | - Stephen L Boehm
- Indiana Alcohol Research Center and Department of Psychology, Indiana University - Purdue University Indianapolis, Indianapolis, IN 46202, United States.
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2
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Bauer MR, Garcy DP, Boehm SL. Systemic Administration of the AMPA Receptor Antagonist, NBQX, Reduces Alcohol Drinking in Male C57BL/6J, But Not Female C57BL/6J or High-Alcohol-Preferring, Mice. Alcohol Clin Exp Res 2020; 44:2316-2325. [PMID: 32945559 DOI: 10.1111/acer.14461] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 09/04/2020] [Indexed: 11/28/2022]
Abstract
BACKGROUND α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors are ionotropic glutamate receptors that have been investigated for their role in modulating alcohol consumption. However, little is known about the role of AMPA receptors in the control of binge-like or free-access alcohol drinking in C57BL/6J or in selectively bred high-alcohol-preferring (HAP) mice. The purpose of this experiment was to assess the role of systemic administration of the AMPA receptor antagonist, 2,3-dioxo-6-nitro-7-sulfamoyl-benzo[f]quinoxaline (NBQX), on alcohol consumption using a model of binge-like drinking, drinking in the dark (DID) and free-access 2-bottle choice (2BC) in male and female C57BL/6J and HAP mice. METHODS C57BL/6J mice were allowed free access to 20% (v/v) alcohol for 2 hours each day beginning 3 hours into the dark cycle for 4 days. On day 5, mice were intraperitoneally injected with one of 4 doses of NBQX (0, 3, 10, or 30 mg/kg; n = 10) 15 minutes before alcohol presentation and were given 4-hour alcohol access (extended DID). HAP mice were given 24-hour free access to 10% (v/v) alcohol and water for 19 days. On day 20, mice were intraperitoneally injected with one of 4 doses of NBQX (0, 3, 10, or 30 mg/kg; n = 9) 15 minutes before alcohol and water presentation. RESULTS In the first 2 hours of DID, at 30 mg/kg, male, but not female C57BL/6J or HAP, mice drank significantly less alcohol compared with controls and 30 mg/kg NBQX did not alter saccharin intake in the males. Although male HAP mice drank significantly less alcohol than female mice following 10 mg/kg NBQX, neither sex exhibited drinking that differed significantly from controls. NBQX did not reduce locomotor behavior at any dose, sex, or genotype. CONCLUSIONS These data suggest that AMPA receptors play a key role in modulating binge-like alcohol consumption without altering saccharin consumption or general locomotion and that this effect is specific to sex and genotype.
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Affiliation(s)
- Meredith R Bauer
- From the, Department of Psychology, Indiana Alcohol Research Center, Indiana University - Purdue University Indianapolis, Indianapolis, Indiana
| | - Daniel P Garcy
- From the, Department of Psychology, Indiana Alcohol Research Center, Indiana University - Purdue University Indianapolis, Indianapolis, Indiana
| | - Stephen L Boehm
- From the, Department of Psychology, Indiana Alcohol Research Center, Indiana University - Purdue University Indianapolis, Indianapolis, Indiana
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3
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Ourdev D, Schmaus A, Kar S. Kainate Receptor Activation Enhances Amyloidogenic Processing of APP in Astrocytes. Mol Neurobiol 2018; 56:5095-5110. [PMID: 30484111 DOI: 10.1007/s12035-018-1427-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 11/13/2018] [Indexed: 12/21/2022]
Abstract
Kainic acid (KA) is an analogue of the excitatory neurotransmitter glutamate that, when injected systemically into adult rats, can trigger seizures and progressive neuronal loss in a manner that mirrors the neuropathology of human mesial temporal lobe epilepsy. However, biomolecular mechanisms responsible for the neuronal loss that occurs as a consequence of this treatment remains elusive. We have recently reported that toxicity induced by KA can partly be mediated by astrocyte-derived amyloid β (Aβ) peptides, which are critical in the development of Alzheimer's disease (AD). Nonetheless, little is known how KA can influence amyloid precursor protein (APP) levels and processing in astrocytes. Thus, in the present study using human U-373 astrocytoma and rat primary astrocytes, we evaluated the role of KA on APP metabolism. Our results revealed that KA treatment increased the levels of APP and its cleaved products (α-/β-CTFs) in cultured U-373 astrocytoma and primary astrocytes, without altering the cell viability. The cellular and secretory levels of Aβ1-40/Aβ1-42 were markedly increased in KA-treated astrocytes. We also demonstrated that the steady-state levels of APP-secretases were not altered but the activity of γ-secretase is enhanced in KA-treated U-373 astrocytoma. Furthermore, using selective receptor antagonists, we showed that the effects of KA is mediated by activation of kainate receptors and not NMDA or AMPA receptors. These results suggest that KA can enhance amyloidogenic processing of APP by activating its own receptor leading to increased production/secretion of Aβ-related peptides from activated astrocytes which may contribute to the pathogenesis of temporal lobe epilepsy.
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Affiliation(s)
- D Ourdev
- Department of Psychiatry, University of Alberta, Edmonton, AB, Canada.,Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, AB, Canada
| | - A Schmaus
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, AB, Canada.,Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Satyabrata Kar
- Department of Psychiatry, University of Alberta, Edmonton, AB, Canada. .,Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, AB, Canada. .,Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada. .,Department of Medicine, University of Alberta, Edmonton, AB, Canada.
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4
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Jaremko WJ, Huang Z, Wen W, Wu A, Karl N, Niu L. Identification and characterization of RNA aptamers: A long aptamer blocks the AMPA receptor and a short aptamer blocks both AMPA and kainate receptors. J Biol Chem 2017; 292:7338-7347. [PMID: 28325839 PMCID: PMC5418036 DOI: 10.1074/jbc.m116.774752] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 03/17/2017] [Indexed: 11/06/2022] Open
Abstract
AMPA and kainate receptors, along with NMDA receptors, represent different subtypes of glutamate ion channels. AMPA and kainate receptors share a high degree of sequence and structural similarities, and excessive activity of these receptors has been implicated in neurological diseases such as epilepsy. Therefore, blocking detrimental activity of both receptor types could be therapeutically beneficial. Here, we report the use of an in vitro evolution approach involving systematic evolution of ligands by exponential enrichment with a single AMPA receptor target (i.e. GluA1/2R) to isolate RNA aptamers that can potentially inhibit both AMPA and kainate receptors. A full-length or 101-nucleotide (nt) aptamer selectively inhibited GluA1/2R with a KI of ∼5 μm, along with GluA1 and GluA2 AMPA receptor subunits. Of note, its shorter version (55 nt) inhibited both AMPA and kainate receptors. In particular, this shorter aptamer blocked equally potently the activity of both the GluK1 and GluK2 kainate receptors. Using homologous binding and whole-cell recording assays, we found that an RNA aptamer most likely binds to the receptor's regulatory site and inhibits it noncompetitively. Our results suggest the potential of using a single receptor target to develop RNA aptamers with dual activity for effectively blocking both AMPA and kainate receptors.
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Affiliation(s)
- William J Jaremko
- From the Department of Chemistry and Center for Neuroscience Research, University at Albany, SUNY, Albany, New York 12222
| | - Zhen Huang
- From the Department of Chemistry and Center for Neuroscience Research, University at Albany, SUNY, Albany, New York 12222
| | - Wei Wen
- From the Department of Chemistry and Center for Neuroscience Research, University at Albany, SUNY, Albany, New York 12222
| | - Andrew Wu
- From the Department of Chemistry and Center for Neuroscience Research, University at Albany, SUNY, Albany, New York 12222
| | - Nicholas Karl
- From the Department of Chemistry and Center for Neuroscience Research, University at Albany, SUNY, Albany, New York 12222
| | - Li Niu
- From the Department of Chemistry and Center for Neuroscience Research, University at Albany, SUNY, Albany, New York 12222
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5
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Chaskiel L, Paul F, Gerstberger R, Hübschle T, Konsman JP. Brainstem metabotropic glutamate receptors reduce food intake and activate dorsal pontine and medullar structures after peripheral bacterial lipopolysaccharide administration. Neuropharmacology 2016; 107:146-159. [PMID: 27016016 DOI: 10.1016/j.neuropharm.2016.03.030] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 03/18/2016] [Accepted: 03/21/2016] [Indexed: 12/20/2022]
Abstract
During infection-induced inflammation food intake is reduced. Vagal and brainstem pathways are important both in feeding regulation and immune-to-brain communication. Glutamate is released by vagal afferent terminals in the nucleus of the solitary tract and by its neurons projecting to the parabrachial nuclei. We therefore studied the role of brainstem glutamate receptors in spontaneous food intake of healthy animals and during sickness-associated hypophagia after peripheral administration of bacterial lipopolysaccharides or interleukin-1beta. Brainstem group I and II metabotropic, but not ionotropic, glutamate receptor antagonism increased food intake both in saline- and lipopolysaccharide-treated rats. In these animals, expression of the cellular activation marker c-Fos in the lateral parabrachial nuclei and lipopolysaccharide-induced activation of the nucleus of the solitary tract rostral to the area postrema were suppressed. Group I metabotropic glutamate receptors did not colocalize with c-Fos or neurons regulating gastric function in these structures. Group I metabotropic glutamate receptors were, however, found on raphé magnus neurons that were part of the brainstem circuit innervating the stomach and on trigeminal and hypoglossal motor neurons. In conclusion, our findings show that brainstem metabotropic glutamate receptors reduce food intake and activate the lateral parabrachial nuclei as well as the rostral nucleus of the solitary tract after peripheral bacterial lipopolysaccharide administration. They also provide insight into potential group I metabotropic glutamate receptor-dependent brainstem circuits mediating these effects.
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Affiliation(s)
- Léa Chaskiel
- CNRS, PsychoNeuroImmunologie, Nutrition et Génétique, UMR 5226, Bordeaux, France; Univ. Bordeaux, PsyNuGen, UMR 5226, Bordeaux, France
| | - Flora Paul
- CNRS, PsychoNeuroImmunologie, Nutrition et Génétique, UMR 5226, Bordeaux, France; Univ. Bordeaux, PsyNuGen, UMR 5226, Bordeaux, France
| | - Rüdiger Gerstberger
- Institut für Veterinär-Physiologie und -Biochemie, Justus-Liebig-Universität Giessen, 35392 Giessen, Germany
| | - Thomas Hübschle
- Institut für Veterinär-Physiologie und -Biochemie, Justus-Liebig-Universität Giessen, 35392 Giessen, Germany
| | - Jan Pieter Konsman
- CNRS, PsychoNeuroImmunologie, Nutrition et Génétique, UMR 5226, Bordeaux, France; Univ. Bordeaux, PsyNuGen, UMR 5226, Bordeaux, France.
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6
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Patel TP, Ventre SC, Meaney DF. Dynamic changes in neural circuit topology following mild mechanical injury in vitro. Ann Biomed Eng 2011; 40:23-36. [PMID: 21994056 DOI: 10.1007/s10439-011-0390-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2011] [Accepted: 08/24/2011] [Indexed: 11/26/2022]
Abstract
Despite its enormous incidence, mild traumatic brain injury is not well understood. One aspect that needs more definition is how the mechanical energy during injury affects neural circuit function. Recent developments in cellular imaging probes provide an opportunity to assess the dynamic state of neural networks with single-cell resolution. In this article, we developed imaging methods to assess the state of dissociated cortical networks exposed to mild injury. We estimated the imaging conditions needed to achieve accurate measures of network properties, and applied these methodologies to evaluate if mild mechanical injury to cortical neurons produces graded changes to either spontaneous network activity or altered network topology. We found that modest injury produced a transient increase in calcium activity that dissipated within 1 h after injury. Alternatively, moderate mechanical injury produced immediate disruption in network synchrony, loss in excitatory tone, and increased modular topology. A calcium-activated neutral protease (calpain) was a key intermediary in these changes; blocking calpain activation restored the network nearly completely to its pre-injury state. Together, these findings show a more complex change in neural circuit behavior than previously reported for mild mechanical injury, and highlight at least one important early mechanism responsible for these changes.
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Affiliation(s)
- Tapan P Patel
- Department of Bioengineering, University of Pennsylvania, 220 S 33rd St, Philadelphia, PA 19104, USA
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7
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Gill MB, Frausto S, Ikoma M, Sasaki M, Oikawa M, Sakai R, Swanson GT. A series of structurally novel heterotricyclic alpha-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptor-selective antagonists. Br J Pharmacol 2010; 160:1417-29. [PMID: 20590632 DOI: 10.1111/j.1476-5381.2010.00784.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND AND PURPOSE A new class of heterotricyclic glutamate analogues recently was generated by incorporating structural elements of two excitotoxic marine compounds, kainic acid and neodysiherbaine A. Rather than acting as convulsants, several of these 'IKM' compounds markedly depressed CNS activity in mice. Here, we characterize the pharmacological profile of the series with a focus on the most potent of these molecules, IKM-159. EXPERIMENTAL APPROACH The pharmacological activity and specificity of IKM compounds were characterized using whole-cell patch clamp recording from neurons and heterologous receptor expression systems, in combination with radioligand binding techniques. KEY RESULTS The majority of the IKM compounds tested reduced excitatory synaptic transmission in neuronal cultures, and IKM-159 inhibited synaptic currents from CA1 pyramidal neurons in hippocampal slices. IKM-159 inhibited glutamate-evoked whole-cell currents from recombinant GluA2- and GluA4-containing alpha-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA) receptors most potently, whereas kainate and NMDA receptor currents were not reduced by IKM-159. Antagonism of steady-state currents was agonist concentration dependent, suggesting that its mechanism of action was competitive, although it paradoxically did not displace [(3)H]-AMPA from receptor binding sites. IKM-159 reduced spontaneous action potential firing in both cultured hippocampal neurons in control conditions and during hyperactive states in an in vitro model of status epilepticus. CONCLUSIONS AND IMPLICATIONS IKM-159 is an AMPA receptor-selective antagonist. IKM-159 and related nitrogen heterocycles represent structurally novel AMPA receptor antagonists with accessible synthetic pathways and potentially unique pharmacology, which could be of use in exploring the role of specific populations of receptors in neurophysiological and neuropathological processes.
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Affiliation(s)
- M B Gill
- Department of Molecular Pharmacology and Biological Chemistry, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA
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8
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Glutamate-stimulated release of norepinephrine in hippocampal slices of animal models of attention-deficit/hyperactivity disorder (spontaneously hypertensive rat) and depression/anxiety-like behaviours (Wistar–Kyoto rat). Brain Res 2008; 1200:107-15. [DOI: 10.1016/j.brainres.2008.01.033] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2007] [Revised: 01/02/2008] [Accepted: 01/03/2008] [Indexed: 11/22/2022]
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9
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Hainsworth AH, Nelson RM, Lambert DG, Green AR, Webb TE. Glutamate receptor-mediated inhibition of L-glutamate efflux from cerebral cortex in vitro. Brain Res 2006; 1114:36-40. [PMID: 16904087 DOI: 10.1016/j.brainres.2006.07.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2005] [Revised: 07/05/2006] [Accepted: 07/13/2006] [Indexed: 11/30/2022]
Abstract
We tested whether glutamate receptor ligands affect oxygen-glucose deprivation-evoked L-glutamate efflux from adult rat cerebrocortical prisms. The uncompetitive NMDA antagonist AR-R15896AR inhibited efflux (IC50 34 microM, 87% maximal inhibition). AMPA/kainate receptor blockade (NBQX, 100 microM) or Group II metabotropic glutamate receptor activation (DCG-IV, 10 microM) inhibited efflux (41%, 67% respectively) but Group I mGluR blockade (CPCCOEt/MPEP, 10 microM) was without effect. These data support a modulatory effect of glutamate receptors on L-glutamate efflux.
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Affiliation(s)
- Atticus H Hainsworth
- Pharmacology Research Group, Leicester School of Pharmacy, De Montfort University, Leicester, LE1 9BH, UK.
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10
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Dravid SM, Murray TF. Spontaneous synchronized calcium oscillations in neocortical neurons in the presence of physiological [Mg(2+)]: involvement of AMPA/kainate and metabotropic glutamate receptors. Brain Res 2004; 1006:8-17. [PMID: 15047019 DOI: 10.1016/j.brainres.2004.01.059] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/27/2004] [Indexed: 10/26/2022]
Abstract
Primary cultures of neocortical neurons exhibit spontaneous Ca(2+) oscillations under zero or low extracellular [Mg(2+)] conditions. We find that mature murine neocortical neurons cultured for 9 days also produce spontaneous Ca(2+) oscillations in the presence of physiological [Mg(2+)]. These Ca(2+) oscillations were action potential mediated inasmuch as tetrodotoxin eliminated their occurrence. AMPA receptors were found to regulate the frequency of Ca(2+) oscillations. In contrast, Ca(2+) oscillations were independent of activation of L-type Ca(2+) channels, and NMDA receptors provided only a minor contribution. Release of intracellular Ca(2+) stores was involved in the oscillatory activity since thapsigargin reduced the amplitude and frequency of the oscillations. S-4-carboxyphenylglycine (S)-4CPG), an antagonist of group I metabotropic glutamate receptor (mGluR), also reduced the amplitude of oscillations. In addition, 1-aminocyclopentane-trans-1,3-dicarboxylic acid (trans-ACPD), a group I mGluR agonist, increased the oscillation frequency, suggesting a critical role for mGluR in the generation of Ca(2+) oscillations. The mGluR-mediated release of intracellular Ca(2+) stores appeared to be mediated by phospholipase C (PLC) since the PLC inhibitor U73122 eliminated the Ca(2+) oscillations. These results indicate that Ca(2+) oscillations in neocortical cultures in the presence of physiologic [Mg(2+)] are primarily initiated by excitatory input from AMPA receptors and involve mobilization of intracellular Ca(2+) stores following activation of mGluR.
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Affiliation(s)
- Shashank M Dravid
- Department of Physiology and Pharmacology, College of Veterinary Medicine, The University of Georgia, Athens, GA 30602, USA
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Kovács I, Simon A, Szárics E, Barabás P, Héja L, Nyikos L, Kardos J. Cyclothiazide binding to functionally active AMPA receptor reveals genuine allosteric interaction with agonist binding sites. Neurochem Int 2004; 44:271-80. [PMID: 14602090 DOI: 10.1016/s0197-0186(03)00137-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The agonist, [3H](-)[S]-1-(2-amino-2-carboxyethyl)-5-fluoro-pyrimidine-2,4-dione ([3H](S)F-Willardiine) binding to functional alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptors of resealed plasma membrane vesicles and nerve endings freshly isolated from the rat cerebral cortex displayed two binding sites (K(D1)=33+/-7 nM, B(MAX1)=1.6+/-0.3 pmol/mg protein, K(D2)=720+/-250 nM and B(MAX2)=7.8+/-4.0 pmol/mg protein). The drug which impairs AMPA receptor desensitisation, 6-chloro-3,4-dihydro-3-(2-norbornene-5-yl)-2H-1,2,4-benzothiadiazine-7-sulphonamide-1,1-dioxide (cyclothiazide, CTZ) fully displaced the [3H](S)F-Willardiine binding at a concentration of 500 microM. In the presence of 100 microM CTZ (K(I(CTZ))=60+/-6 microM), both the antagonist [3H]-1,2,3,4-tetrahydro-6-nitro-2,3-dioxo-benzo(F)quinoxaline-7-sulfonamide ([3H]NBQX: K(D)=24+/-4 nM, B(MAX)=12.0+/-0.1 pmol/mg protein) and the high-affinity agonist binding showed similar affinity reduction ([3H](S)F-Willardiine: K(D)=140+/-19 nM, B(MAX)=2.9+/-0.5 pmol/mg protein; [3H]NBQX: K(D)=111+/-34 nM, B(MAX)=12+/-3 pmol/mg protein). To disclose structural correlates underlying genuine allosteric binding interactions, molecular mechanics calculations of CTZ-induced structural changes were performed with the use of PDB data on extracellular GluR2 binding domain dimeric crystals available by now. Hydrogen-bonding and root mean square (rms) values of amino acid residues recognising receptor agonists showed minor alterations in the agonist binding sites itself. Moreover, CTZ binding did not affect dimeric subunit structures significantly. These findings indicated that the structural changes featuring the non-desensitised state could possibly occur to a further site of the extracellular GluR2 binding domain. The increase of agonist efficacy on allosteric CTZ binding may be interpreted in terms of a mechanism involving AMPA receptor desensitisation sequential to activation.
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Affiliation(s)
- Ilona Kovács
- Department of Neurochemistry, Chemical Research Center, Hungarian Academy of Sciences, 1025 Pusztaszeri út 59-67, Budapest, Hungary.
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12
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Allison C, Pratt JA. Neuroadaptive processes in GABAergic and glutamatergic systems in benzodiazepine dependence. Pharmacol Ther 2003; 98:171-95. [PMID: 12725868 DOI: 10.1016/s0163-7258(03)00029-9] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Knowledge of the neural mechanisms underlying the development of benzodiazepine (BZ) dependence remains incomplete. The gamma-aminobutyric acid (GABA(A)) receptor, being the main locus of BZ action, has been the main focus to date in studies performed to elucidate the neuroadaptive processes underlying BZ tolerance and withdrawal in preclinical studies. Despite this intensive effort, however, no clear consensus has been reached on the exact contribution of neuroadaptive processes at the level of the GABA(A) receptor to the development of BZ tolerance and withdrawal. It is likely that changes at the level of this receptor are inadequate in themselves as an explanation of these neuroadaptive processes and that neuroadaptations in other receptor systems are important in the development of BZ dependence. In particular, it has been hypothesised that as part of compensatory mechanisms to diazepam-induced chronic enhancement of GABAergic inhibition, excitatory mechanisms (including the glutamatergic system) become more sensitive [Behav. Pharmacol. 6 (1995) 425], conceivably contributing to BZ tolerance development and/or expression of withdrawal symptoms on cessation of treatment, including increased anxiety and seizure activity. Glutamate is a key candidate for changes in excitatory transmission mechanisms and BZ dependence, (1) since there are defined neuroanatomical relationships between glutamatergic and GABAergic neurons in the CNS and (2) because of the pivotal role of glutamatergic neurotransmission in mediating many forms of synaptic plasticity in the CNS, such as long-term potentiation and kindling events. Thus, it is highly possible that glutamatergic processes are also involved in the neuroadaptive processes in drug dependence, which can conceivably be considered as a form of synaptic plasticity. This review provides an overview of studies investigating changes in the GABAergic and glutamatergic systems in the brain associated with BZ dependence, with particular attention to the possible differential involvement of N-methyl-D-aspartate and alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors in these processes.
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Affiliation(s)
- C Allison
- Department of Physiology and Pharmacology, Strathclyde Institute for Biomedical Sciences, University of Strathclyde, Taylor Street, G4 ONR, Glasgow, UK
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Martin A, Récasens M, Guiramand J. DNQX-induced toxicity in cultured rat hippocampal neurons: an apparent AMPA receptor-independent effect? Neurochem Int 2003; 42:251-60. [PMID: 12427479 DOI: 10.1016/s0197-0186(02)00089-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
To evaluate the involvement of AMPA receptor activation in neuronal cell death and survival, rat hippocampal neurons in culture were treated with AMPA receptor antagonists. A 46 h treatment with 6,7-dinitroquinoxaline-2,3-dione (DNQX), added 2 h after cell plating, induces a dose-dependent neurotoxicity. Similar effects are also observed in more mature hippocampal neurons (treatment at 14 days in vitro). DNQX toxic effect is neuron-specific since cultured hippocampal glial cells are unaffected. Attempts to characterise the site of action of DNQX suggest that ionotropic glutamate receptors would not be implicated. Indeed, (i) other AMPA receptor antagonists are either ineffective or only moderately efficient in mimicking DNQX effects; (ii) AMPA alone or in the presence of cyclothiazide, as well as, other AMPA receptor agonists, do not reverse DNQX action; (iii) DNQX neurotoxicity is not likely to involve blockade of NMDA receptor glycine site, since this effect is neither mimicked by 7-chlorokynurenate nor reversed by D-serine. Thus, DNQX toxicity in cultured hippocampal neurons is apparently mediated through an ionotropic glutamate receptor-independent way.
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Affiliation(s)
- Alexandra Martin
- Laboratoire de Plasticité Cérébrale, CNRS UMR5102, Université Montpellier II, Place E Bataillon, cc090, 34095 Montpellier Cedex 5, France
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Lindén AM, Yu H, Zarrinmayeh H, Wheeler WJ, Skolnick P. Binding of an AMPA receptor potentiator ([3H]LY395153) to native and recombinant AMPA receptors. Neuropharmacology 2001; 40:1010-8. [PMID: 11406192 DOI: 10.1016/s0028-3908(01)00013-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
LY395153 is a member of a newly described class of arylpropylsulfonamide AMPA receptor potentiators. Here, we characterize and compare [(3)H]LY395153 binding to native AMPA receptors from rat cerebral cortex and recombinant human GluR4(flip) receptors expressed in HEK293 cells. L-Glutamate and AMPA increased [(3)H]LY395153 binding to both native and recombinant AMPA receptors in a concentration dependent and stereoselective manner; this effect of AMPA receptor agonists reflects an apparent increase in ligand affinity. In the presence of L-glutamate (500 microM), [(3)H]LY395153 binding is saturable; the affinity of this radioligand is slightly, albeit statistically significantly higher at human GluR4(flip) (K(d)=55.6+/-5.3nM) than rat cortical receptors (K(d)=110+/-15.1nM). NBQX competitively inhibited L-glutamate-induced increases in [(3)H]LY395153 binding in both native and recombinant receptors, whilst LY303070 (the active isomer of GYKI53655) noncompetitively inhibited this effect in native, but not recombinant receptors. The prototypic AMPA receptor potentiator cyclothiazide competitively inhibited [(3)H]LY395153 binding with a potency (K(i) approximately 7 microM) comparable to EC(50) values reported in electrophysiological studies. In contrast, the structurally unrelated AMPA receptor potentiator CX 516 did not inhibit [(3)H]LY395153 binding at concentrations of up to 600 microM. Further, at concentrations reported to facilitate AMPA receptor desensitization, thiocyanate acts as a competitive inhibitor of [(3)H]LY395153 binding. [(3)H]LY395153 binding was unaffected by a variety of structurally (and mechanistically) diverse compounds tested at a concentration of 10 microM. These data indicate [(3)H]LY395153 is a useful probe for labeling a unique modulatory site on both native and recombinant AMPA receptors.
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Affiliation(s)
- A M Lindén
- Lilly Research Laboratories, Lilly Corporate Center, DC 0510, Indianapolis, IN 46285, USA
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15
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Marin C, Jimenez A, Bonastre M, Chase TN, Tolosa E. Non-NMDA receptor-mediated mechanisms are involved in levodopa-induced motor response alterations in Parkinsonian rats. Synapse 2000; 36:267-74. [PMID: 10819904 DOI: 10.1002/(sici)1098-2396(20000615)36:4<267::aid-syn3>3.0.co;2-y] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Chronic dopaminomimetic administration to parkinsonian animal models or Parkinson's disease patients leads to characteristic alteration in motor response. Previous studies suggested that the nonphysiologic stimulation of dopaminergic receptors on striatal medium spiny neurons enhances the synaptic efficacy of juxtaposed glutamate receptors of the N-methyl-D-aspartate (NMDA) subtype. Resultant NMDA receptor sensitization due to differential changes in subunit phosphorylation appears to favor alterations in striatal output in ways that influence motor function. To detail the involvement of NMDA receptors further as well as to determine whether similar functional changes might develop in alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptors, the effects of selective antagonist of AMPA receptors (6-nitro-7-sulfamoyl-benzo[f]-quinoxaline-2,3 (1H,4H)-dione sodium salt, NBQX, 10 mg/kg) on levodopa-induced response alterations in 6-hydroxydopamine (6-OHDA) lesioned rats were compared with drugs which act competitively (3-(+/-)-2-carboxypiperazin-4-yl)-propyl-1-phosphonicacid, CPP, 6.25 mg/kg) or noncompetitively (dextromethorphan, 40 mg/kg) to block NMDA receptors, or a nonselective inhibitor of glutamatergic transmission (2-amino-6-trifluoromethoxy benzothiazole, riluzole, 5 mg/kg). We found that the shortened duration of the motor response to levodopa, which underlies human wearing-off fluctuations, was reversed to a similar degree by the acute coadministration of CPP, NBQX, or riluzole (n = 4-6) but dextromethorphan did not. These observations strengthen the possibility that a reduction in levodopa-associated changes in motor response by inhibitors of glutamatergic transmission acting generally or selectively at the glutamate binding-sites may relate to their ability to attenuate pathologic gain in striatal glutamatergic function. The capacity of NBQX to reverse these altered responses suggests that an enhanced synaptic efficacy of striatal AMPA receptors may also participate in the generation of these motor response changes in levodopa-treated parkinsonian rats.
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Affiliation(s)
- C Marin
- Laboratori de Neurologia Experimental, Servei de Neurologia, Institut d'Investigacions Biomèdiques Agustí Pi i Sunyer (IDIBAPS), Barcelona, Spain.
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Cyr M, Ghribi O, Di Paolo T. Regional and selective effects of oestradiol and progesterone on NMDA and AMPA receptors in the rat brain. J Neuroendocrinol 2000; 12:445-52. [PMID: 10792584 DOI: 10.1046/j.1365-2826.2000.00471.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We investigated the effect of 10 months ovariectomy and a correction therapy, 2 weeks before the rats were killed, of oestradiol, progesterone or their combination on NMDA and AMPA receptor binding in the hippocampus, dentate gyrus, striatum, nucleus accumbens and frontal cortex of the rat brain as well as on amino acid levels in frontal cortex. NMDA and AMPA binding densities were assayed by autoradiography using, respectively, L-[3H]glutamate and [3H]AMPA; amino acid concentrations were measured by high performance liquid chromatograhy (HPLC) coupled with UV detection. Ovariectomy was without effect on NMDA and AMPA binding density in all brain regions assayed except in the hippocampal CA1 region and dentate gyrus where it decreased NMDA binding density compared to intact rats values. Oestradiol restored and increased NMDA binding density in the CA1 subfield and the dentate gyrus of ovariectomized rats but, by contrast, it decreased binding density in the striatum and in the frontal cortex while having no effect in the CA2/3 subfield of the hippocampus and in the nucleus accumbens. Oestradiol was without effect on AMPA binding density in the hippocampus and the dentate gyrus but it reduced AMPA binding density in the striatum, the frontal cortex and the nucleus accumbens. Progesterone, and oestradiol combined with progesterone, decreased NMDA but not AMPA binding density in the frontal cortex of ovariectomized rats, and they were without effect on these receptors in the other brain regions assayed. Amino acid concentrations in the frontal cortex were unchanged after ovariectomy or steroid treatments. The effect of oestradiol in the hippocampus confirmed in the present study and our novel findings in the frontal cortex, striatum and nucleus accumbens may have functional significance for schizophrenia and neurodegenerative diseases.
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Affiliation(s)
- M Cyr
- Centre de Recherche en Endocrinologie Moléculaire du CHUQ, and Faculté de pharmacie, Université Laval, Québec, Canada
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Mitsikostas DD, Sanchez del Rio M, Waeber C, Huang Z, Cutrer FM, Moskowitz MA. Non-NMDA glutamate receptors modulate capsaicin induced c-fos expression within trigeminal nucleus caudalis. Br J Pharmacol 1999; 127:623-30. [PMID: 10401552 PMCID: PMC1566054 DOI: 10.1038/sj.bjp.0702584] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
1. We examined the effects of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/kainate receptor antagonists 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and 1,2,3,4-tetrahydro-6-nitro-2,3-dioxo-benzol[f]quinoxaline-7-sulpho namide (NBQX), the kainate receptor antagonists gamma-(R-)-glutamylaminomethanesulphonic acid (GAMS) and 6,7,8,9-tetrahydro-5-nitro-1H-benz[g]indole-2,3-dione-3-oxime (NS-102), and the group III metabotropic glutamate receptor (mGluR) agonist 2-amino-4-phosphono-S-butanoic acid (L-AP4) on c-fos-like immunoreactivity (c-fos LI) in trigeminal caudalis (Sp5C), lateral reticular (LRt), medullary reticular (Md) and solitary tract (Sol) nuclei, after intracisternal injection of capsaicin in urethane anaesthetized Sprague-Dawley rats. 2. Few c-fos labelled cells were observed within Sp5C in capsaicin-vehicle treated animals. The number of positive c-fos cells increased by 17 fold after intracisternal capsaicin (5 nmol) administration. 3. Pretreatment with CNQX (0.02, 0.1, 0.6, 3 and 15 mg kg-1) or NBQX (0.01, 0.1 and 1 mg kg-1), administered intraperitoneally 15 min before capsaicin, significantly reduced labelled cells within Sp5C by a maximum of 45 and 34%, respectively. The number of c-fox LI cells within LRt, Md and Sol was not affected. Pretreatment with L-AP4 (1, 3 and 10 mg kg-1) decreased the number of Sp5C c-fos LI cells by a maximum of 30%, whereas GAMS (1 and 10 mg kg-1) and NS-102 (1 and 5 mg kg-1) did not show any significant effect. 4. These results suggest that blockade of AMPA receptors, but not kainate receptors, or the activation of group III mGluRs, decrease the response of Sp5C neurons to trigeminovascular activation. Thus, in addition to NMDA receptors, mGluRs and AMPA receptors may modulate cephalic pain and may provide a potential therapeutic target for antimigraine drugs.
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Affiliation(s)
- Dimos D Mitsikostas
- Stroke & Neurovascular Regulation Laboratory, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Boston, Massachusetts, MA 02129, U.S.A
| | - Margarita Sanchez del Rio
- Stroke & Neurovascular Regulation Laboratory, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Boston, Massachusetts, MA 02129, U.S.A
| | - Christian Waeber
- Stroke & Neurovascular Regulation Laboratory, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Boston, Massachusetts, MA 02129, U.S.A
| | - Zhihong Huang
- Stroke & Neurovascular Regulation Laboratory, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Boston, Massachusetts, MA 02129, U.S.A
| | - F Michael Cutrer
- Stroke & Neurovascular Regulation Laboratory, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Boston, Massachusetts, MA 02129, U.S.A
| | - Michael A Moskowitz
- Stroke & Neurovascular Regulation Laboratory, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Boston, Massachusetts, MA 02129, U.S.A
- Author for correspondence:
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Abstract
A wide variety of mechanisms have been identified that can regulate the alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA)-receptor complex. Modulation has been shown to occur at the nucleic acid level via RNA editing and alternative splicing. At the posttranslational level, processes such as phosphorylation, glycosylation, chemical modification of reactive groups on the receptor proteins, interaction with a putative receptor-associated modulatory protein, and changes in the lipid environment have been reported to regulate receptor binding and function. In this review, we discuss general aspects of the cell biology, pharmacology, and function of AMPA receptors. In particular, we focus on some factors shown to modulate agonist binding and discuss possible molecular mechanisms underlying the regulation observed.
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Affiliation(s)
- K K Dev
- Department of Anatomy, University of Bristol, Medical School, UK
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Effects of thiocyanate and AMPA receptor ligands on (S)-5-fluorowillardiine, (S)-AMPA and (R,S)-AMPA binding. Eur J Pharmacol 1997. [DOI: 10.1016/s0014-2999(97)89182-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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